BASED ON A STUDY OF THE MALE GENITAL ARMATURE. 31 
the stem of the clasper and takes a course almost at right angles to the latter 
until it reaches the middle line, when it bends suddenly towards the distal margin 
of the claspers so that a large rectangular projection is formed, the breadth of 
which is greater than the width of the narrowest portion of the superior clasper ; 
bristles on the outer lateral portion similar to those in G. longipalpis but 
relatively shorter. Juxta (j) with a very narrow slit on the distal portion. 
Bristles of the editum (¢) half the length of the superior claspers. Inferior 
claspers (7c) pointed, basal portions very broad and apparently meeting in the 
median line. 
The morphological differences between this species and G. longipalpis, though 
they may appear at first very slight, are really well marked and pronounced, as 
may be gathered from the following table and the accompanying illustrations :-— 
Comparative Table of the Morphological Characters of the Superior Claspers, S¢., of 
G. pallidipes and G. longipalpis. 
G. longipal pis. G, pallidipes. 
Heel or posterior Outer lateral margin Outer lateral margin 
lateral tooth. taking same contour generally curved in- 
as the margin of the wards, 
clasper. 
Single long hair on Long and capable of Short and not capable 
distal margin. overlapping —_corre- of overlapping hair 
sponding hair on op- on opposite clasper. 
posite clasper. 
Inner flange-like ex- Greatest breadth about Breadth greater than the 
tension of superior one-fourth the width width of the narrowest 
clasper. of the narrowest por- portion of the stem. 
tion of stem. 
Longest hairs of Equal in length to the One-half the length of 
editum. superior clasper. the superior clasper. 
In the paper recently published by me in the Annals of Tropical Medicine 
and Parasitology (Vol. IV., p. 370) I called attention to the fact that I had 
examined a single example of what had been considered an authentic specimen 
of G. pallidipes, Austen, and that it proved to be morphologically identical with 
G. longipalpis, Wied. In the light of this discovery I felt that the only course 
open to me was to treat G. pallidipes as a colour variety of G. longipalpis. The 
specimen in question has, however, proved to be a variety of the latter with pale 
front and middle tarsi, so that this insect is evidently given to occasional 
variation in the colour of the tarsi, though at the present moment this would 
seem to be an isolated instance. 
Thanks to the kindness of Mr. HE. EK. Austen, of the British Museum of 
Natural History, I have been able to examine the genitalia of seven males 
of his G. pallidipes,* and it was by the examination of this material that 
* All labelled from ‘“ Machakos, B. E. Africa, Presented by Tsetse-Fly Committee of the 
Royal Society per Lt.-Col. Bruce.” 
